self : (1) individual’s typical character or behavior (2) individual’s temporary behavior or character (3) the union of elements (as body, emotions, thoughts, and sensations) that constitute the individuality and identity of a person — Webster

Self is a reference by an individual to the same individual person. This reference is necessarily subjective and it follows that self is a reference by a subject to the same subject. The sense of having a self – or self-hood – should, however, not be confused with subjectivity itself. Ostensibly, there is a directedness outward from the subject that refers inward – back to its “self” (or itself).

The first-person perspective distinguishes self-hood from personal identity. Whereas “identity” is sameness, self-hood implies a first-person perspective. Conversely, we use “person” as a third-person reference. Finally, the self is distinguishable from “others”. Including the distinction between sameness and otherness, the self versus other is a research topic in contemporary philosophy) and contemporary phenomenology (see also psychological phenomenology), psychology, psychiatry, neurology, and neuroscience. — Wikipedia